Japanese collaborative study to assess inter-laboratory variation in factor VII activity assays

A Serendipitous Finding of Coagulation Factor VII Deficiency in Two Asymptomatic Patients

Congenital Factor VII (FVII) deficiency is a rare autosomal recessive disorder with a prevalence of approximately 1:500,000. It plays a crucial role in initiating coagulation by activating Factors IX and X. Diagnosis typically involves prolonged prothrombin time (PT) and varies widely in clinical presentation. Management includes fresh frozen plasma (FFP), prothrombin complex concentrates (PCC), and recombinant activated FVII (rFVIIa), with rFVIIa often preferred due to its safety and efficacy. We present two pediatric cases: a five-year-old boy with a prolonged PT at 55% and FVII levels at 25.1%, and a two-year-old boy with a PT at 24% and FVII levels at 4.6%. Both cases highlight the importance of thorough hemostatic evaluation and tailored management strategies in FVII deficiency.

Factor VII Deficiency: Clinical Phenotype, Genotype and Therapy

Factor VII deficiency is the most common among rare inherited autosomal recessive bleeding disorders, and is a chameleon disease due to the lack of a direct correlation between plasma levels of coagulation Factor VII and bleeding manifestations. Clinical phenotypes range from asymptomatic condition—even in homozygous subjects—to severe life-threatening bleedings (central nervous system, gastrointestinal bleeding). Prediction of bleeding risk is thus based on multiple parameters that challenge disease management. Spontaneous or surgical bleedings require accurate treatment schedules, and patients at high risk of severe hemorrhages may need prophylaxis from childhood onwards. The aim of the current review is to depict an updated summary of clinical phenotype, laboratory diagnosis, and treatment of inherited Factor VII deficiency.

Factor VII Deficiency: From Basics to Clinical Laboratory Diagnosis and Patient Management

Factor VII (FVII) deficiency is a rare inheritable bleeding disorder affecting 1/500 000 individuals. Clinical manifestations are heterogeneous, from asymptomatic to severe and potentially fatal bleeding. These clinical manifestations do not correlate well with FVII plasma levels. For this reason, FVII-deficient patient management during surgery or for long-term prophylaxis remains challenging. Laboratory testing for FVII activity is, however, the first-line method for FVII deficiency diagnosis and is helpful for managing patients in combination with clinical history. Additional testing consists of FVII immunoassay and genetic testing. Genetic abnormalities on the FVII gene are heterogeneous and can translate into quantitative or qualitative defects. Some of the latter can react differently with different thromboplastins; this can be misleading for the laboratory as no consensus exists at present on an FVII deficiency diagnosis methodology. Indeed, no single test is able to predict accurately the bleeding risk. This review provides a broad picture of inherited and acquired FVII deficiency with a particular focus on laboratory diagnosis.

Heterozygous congenital Factor VII deficiency with the 9729del4 mutation, associated with severe spontaneous intracranial bleeding in an adolescent male

BACKGROUND

In congenital Factor (F) VII deficiency bleeding phenotype and intrinsic FVII activity levels don't always correlate. Patients with FVII activity levels <30% appear to have a higher bleeding propensity, but bleeding can also occur at higher FVII activity levels. Reasons for bleeding at higher FVII activity levels are unknown, and it remains challenging to manage such patients clinically.

CASE

A 19year old male with spontaneous intracranial hemorrhage and FVII activity levels of 44%, requiring emergent surgical intervention and a strategy for FVII replacement. Genotyping showed the rare heterozygous FVII 9729del4 mutation. Bleed evacuation was complicated by epidural abscess requiring craniectomy, bone graft procedures, and prolonged administration of recombinant human (rh) activated FVII (FVIIa). The patient recovered without neurological deficits, and remains on prophylactic low dose treatment with rhFVIIa in relation to risky athletic activities.

CONCLUSION

For clinicians, it is important to recognize that effects of rhFVIIa within these pathways are independent of its contribution to blood clot formation and cannot be assessed by clotting assays. Reduced FVII levels should therefore not be dismissed, as even a mild reduction may result in spontaneous bleeding. Treatment of mild FVII deficiency requires a careful case-by-case approach, based on the clinical scenario.